Manufacture of carbon disulphide



PATENT OFFICE.

PHILIP? SIEDLER, 0F GRIESHEIM-ON-THE-MAIN, GERMANY, ASSIG-NOR TO I. G.

FARBENINDUSTRIE AKTIENGESELLSCHAFT, OF FRANKFORT-ON-THE-MAIN, GER- JEANY.

MANUFACTURE OF CARBON DISULPHIDE.

No Drawing. Origir This invention relates to the manufacture of carbon disul hide CS more especially.

to the method of charging the furnaces with charcoal, and stands in relation to the invention described in my copending'application Serial No. 40,386, filed J une 29, 1925, from which this application has been divided out.

Llt is well known that the output in the production of carbon disulphide essentially depends on the quantity of moisture entering the heating zone, owing to the fact that the presence of water would result in the formation of carbon monoxid, carbon dioxid and sulphuretted hydrogen the latter in particular, involvinga loss of sulphur.

flitherto in practice nothing better was known than to remove the adsorbed water from the charcoal (or other sort ofporous coal) by preliminary drying, with or without the application of vacuum, or, in some cases, by gently preheating thecharcoal or the like in the upper parts of the shaft of the furnace itself or in a separate container and drawing off, with the carbon disulphide,-

the gases and water va ours produced, which latter react with t e carbon disulphide to, form sulphuretted hydrogen. Consequently one was obliged to separate, in a eculiar washing plant, from t e big quantlty of Waste gases the carbon disulphide contained therein and to provide for a sulphur regenerating plant (system of (Hans-Chance or the like), whereby a great expense for attendance and" heating materials was necessitated.

Now I have recognized that by removing the adsorbed water, or by moderate heating to red-heat the best conditions for attaining the maximum output of carbon disulphide and avoiding the undesired formation of sulphretted hydrogen, are by no means attained; and that the most favorable conditions are on] realizable when also the latent source of ormation of steam and other noxious gases (or gases,v the formation of which is connected with the consumption of sulphur) is removed. As such source I "consider the presence of fixed oxygen and hydrogen in the charcoal, originating fron. the cellulose or lignin molecules of the wood. From the fact that common marketable clan-coal, by heating the same application filed June 29. 1925, Serial No. 40.386, and in Germany July '3. 1924. Divided and this application filed November 28, 1925.

Serial No. 72,041.

up to l000 (l, loses from 20 to 30 per cent of its weight, it may easily be understood what an important part the available amount of water vapour and gas-forming substances plays.

'lherel'ore my invention consists in feeding the carbon disulphide furnace only with charcoal, which has been practically completely calcined, that is to say, at tempertnres from 100U to 12tl0 3.,and that in such a manner that the charcoal runs in an ineendescent state and free from the access of air from a preheating furnace arranged at a corresponding level to the carbon disul hide furnace.

or carrying out my invention I pref:

'erably employ an apparatus as follows 2- .The preheating device is made to form an electric resistance furnace, in which the nonconductlng raw charcoal to be calcined is charged above incandescent conductive charcoal. In this furnace, a shaft lined with bricks is formed, in which an upper movable electrode and one or more station ary bottom electrodes are provided. The bottom electrode consists either of a base plate provided with an outlet opening, or 1t may be in the form of single electrodes, the ends of which project from the masonry into the interior of the furnace shaft; in both cases the charge of charcoal forms an electric resistance between the upper and the bottom electrode or electrodes.

The outlet opening at the bottom of the preheating furnace is connected'with the mlet opening of the carbon disulphide furnace by a pipe which .ma be closed or opened b usual means if esired, so that the comp etely calcined charge ma be run intermittently into the carbon dlsulphide.

furnace without carbon disulphide vapours entering the preheating furnace. The gases produced by the preheating operation may be continuously or intermittently. withdrawn from the closed furnace by means of suitable tapping devices. When the carbon disulphide 'furnace proper is heated by electricity, the preheating of the charcoal in a separate kiln does not entail a noticeable increase of thetotal amount of electric en ergy required. as compared with the process hitherto used. However, the little loss merely caused by heat radiation is more than compensated for by the advantages which are connected with the use of completely calcined charcoal.

.An apparatus for carrying into practice the present invention is described in my c'opending application Ser. No. 40,386.

With my improved process, I not only attain an increased out ut of carbon disulphide, the quantity of waste gases saturated with carbon disulphide being reduced. and at the same time the production of sulphuretted hydrogen being avoided, but also a purer carbon disulphide is produced pontaining, by far, less sulphuretted hydrogen, fewer organc sulphur compounds and fewer dust particles, for the formation pf dust connected wth the heating, in this case, no longer takes lace in the producer itself. Furthermore t e eflective power of producer is increased by the upper layer of charcoal cntcrin the producer at a term participates in conducting the electric current.

My process is especially a plicable to furnaces in which the wholeciarge of the shaft servesas resistance, but also with corrcspondin adaptation of the apparatus, to all other lcinds of shaft or retort furnaces for the production of carbon disulphide.

I claim The process of charging carbon disulphide producers with charcoal, which process consists in calcining the charcoal at temperatures of 1000 C. at least, and then introducing the thus calcined charcoal into the producer whilst preventing the access of air.

In testimony whereof I aflix my si nature.

PHILIPP SIED ER. 

